Ultranova
As the interdiction collapses, massive feedback waves of the core's influence ripple through the space nearby, magnifying greatly the imprecision of the non-Anvil's weaponry, as such, a great portion of the Yazari projectiles miss their target completely, or land in other, uninportant areas of the megastructure, provoking unrelenting yet inconsequentional damage. Another good portion of the plasma missiles is stopped by the megastructure's own defensive systems, the core's influence massively disturbing the anti-grav of the missiles combined with the sheer onslaught of thousands of projectiles provided enough stopping power to save most of the cannons.
However, The Anvil did not go unscathed, as four of the missiles still landed on the loaded cannons, providing a great fireworks show as the armed nuclear devices inside of the shell of the cannon detonated due to the damage provoked by the missiles, pushing the cannon's build violently back into the platform where it came from and collapsing the structure around it as the shockwave rang the metal as it was water, forming waves of destructe that didn't compromise the megastructure's whole integrity, but provided that entire sections of it were unusable until after a long period of repair. In total four loaded cannons were destroyed, and one unloaded cannon was put out of commission for the rest of the battle, such a strike effectively put The Anvil's firepower at 1/3, but the damage to its production capabilities was far more fatal than that.
Meanwhile, as one portion of the megastructure was attacked, other cannons were busy in the acquisition of the new targets, being loaded and in full capability of attack, in a counter to the Yazari and Xorxian's efforts, a salvo of 3 more cannon shots was dished out towards them, the close proximity to the megastructure proves the aim to be fatal as the massive once-monolithic projectiles split into tens of thousands of smaller metallic rods, each capable of reducing battleships to a mess of mangled metal in its own right as they littered the black vastness of space. The other cannons swiveled around to face the fleets that awaited outside of the interdiction bubble.
The Voghus' combined beams, being in their own right deadly weapons, burned at the point defenses fired at them and struck two of the armed cannons that were swiveling around, whilst the enourmously thick armor of the cannons would normally hold back against the beams, it seems that they had a stroke of luck as the beams hit the cannon's back and went directly into the gun's chamber, detonating the nuclear devices that would otherwise be used to reduce more fleets to fields of debris. The cannons proceeded to detonate in a similar manner, carving gaping holes into the megastructure's surface.
Great quantities of workforce were being re-routed to repair and tend to the equally great fires that these explosions provoked, entire assembly lines were destroyed annd tens of thousands of casualties were generated with the collapse of almost half of the firepower of the megastructure, the forge master was not pleased with the resutls of such attacks, he was even less pleased as the Imperium's transmission came pointing out their surrender. He sits on his blue metal throne and ponders about the next step as the structure still rings out in pain at the wake of the massive detonations.